Process of dyeing cellulose acetates



Patented July 28, 1925.

RENE GLAV'EL, OF BASEL, SWITZEIRLAND.

PROCESS OF PYEING GELLULOSE AGETATES. y

i No Drawing.

To all whom it. may concern: I

Be it known that I RENE GLAVEL, a citizen of the Swiss Republic, of Basel, Switzerland, have invented a certain new and useful Improved Process of Dyeing Cellulose Acetates, of which the following is a specification.

' This invention relates to the dyeing of cellulose acetates in artificial silk, film or other form, in black shades.

In the specification of my United States Patent No. 1,448,432, it is stated and shown that certain groups n dyestufl's are capable -of imparting to the 'dyestufi's containing them an increased aifinity for the acetyl celluloses in artificial silk or other form, as such dyestufls 0 into chemical reaction or present some ot er favourable physical condit-ion relatively to the acetyl celluloses, it

being immaterial whether these dyestufis are in dissolved or undissolved form in the dyebaths. Amongst these active groups there were mentioned: amido, imino, imide-, and

acidylaminogroups (H-N-CO.R, in which R stands for alkyl or aryl). ,Amongst others, aniline black was given as an example of a dyestufi' with active groups. Owing to its active groups this dyestufi can be brought into the fibre direct or in suspended form, but better by impregnating the fibre with aniline hydrochloride and developing. Technical working in the latter case has shown, however, that in spite of the cheapness of this aniline black, the fibre is sometimes affected in sympathy, so that it was of advantage to find a development black which would fulfil the textile demands in every respect. As a possible development black, diphenylamine containing two active groups was investigated, and it was found that with this the method of application usual with cotton was not suitable for acetyl celluloses, such for example as artificial silks, as only dull, uneven black dyeing-of the goods was obtained.

In further constructive development, a process has now been found which 1s believed to fulfil all the technical requirements, as acetate silk fibres for example are neither weakened nor Suffer in lustre by it, and moreover it enables any dye works which are not equipped for aniline black dyeing, to

obtain nevertheless a handsome deep black siinilar to aniline black.

According to the invention cellulose ace-' tates are dyed with diphenyl black base in Application filed October 5, 1922. Serial No. 592,604.

presence of an aliphatic carboxylic acidor acids, with or without soluble chloride salts,

and with or without protective colloids, and developed.

The following examples illustrate how the invention may be carried out, but it will be understood that these are-given by way of example only, and can be varied greatly without departing from the spirit of the invention. V I

To dye 1 kg. of acetate silk, stock soluwhole is made up to 1250 cc. solution.

-Dyeba.th: This is prepared so that the weight of the diphenyl black base'corresponds to 12 per centof the weight of goods.

Example: Dyebath for 1 kg. acetyl celluthe hec -750 cc. stock solution I, 750 cc. stock solution II, the whole diluted with water to about l 45% litres.

-Method of operation: The dyeing is performed in the cold. -The goods-are turned two to three times in the bath and soaked for halfan hour. the bath and whizzed.

Developing: The oxidation or development is effected by placing the goods in a drying room at 80 (1, preferably turning the goods on the rods once or twice during about an hour. After the development time mentioned the goods are washed twice, soaped at 5060.C., then rinsed with two soft waters and one hard water and soured.

Example B.

One may also work as follows Stock solution: %0 gr. diphenyl black base, 50000. 80% acetic acid, 500 cc. water.

They are then removed from ming of raw natural silk with soap solutions) rite, chloride of and oxidized or develo are added. This dye bath is warmed to 50 C. and the goods are turned in the bath for about an hour. Then 50 grams of sodium acetate are added to the bath and the goods are treated in it for about an hour more at 60 C. They are then given a short rinsing ed in a second bath.

Developing bath: Th1s consists of'20 liters Water, 100 gr. ammonium persulphate.

v The goods are oziidized for about an hour. They are then washed, soa rinsed with soft water and with and brightened. a v

One can however also work by developing in the exhausted dyebath, with careful addition of oxidizing agents such as hypochlo ime, persulphate or perhohard water,

rate.

What I- claim and desire to secure by Letters Patent is 1. Process far dyeing acetyl cellulose in black shades com rising treating the acetyl cellulose with dip enyl black base in presence of at least one aliphatic carboxylic acid 'iind developing the'dye' on the acetyl celluose.

2. Process for dyeing acetyl cellulose in black shades, comprising treating the acetyl cellulose with diphenyl black basein presence of at least one allphatic carboxylic acid and at least one soluble chloride salt, and developing the dye on the acetyl cellulose.

3. Processlfor dyeing acetyl cellulose in black shades, comprising treating the acetyl cellulose with diphenyl black base in presed at 50 0.,

ence of at least one alilphatic carboxylic acid and protective colloi dye on the acetyl 4. Process for dyeing acetyl cellulose in black shades, complris'ing treating the acetyl cellulose with dip enyl black base in presence of at leat one at least one soluble chloride salt, and protec. tive colloid, and developing the dye on the acetyl cellulose.

5. ?rocess for black shades, comprising treating the acetyl cellulose with diphenyl black base in prescellu ose.

ence of acetic acid, and developing the dye on the acetyl cellulose.

6. Process for dyeing acetyl cellulose in black shades, comprising treating the acetyl cellulose with ence of acetic acid and at least one soluble chloride salt and developing'the dye on the. acetyl cellulose. I

7. Process for dyeing acetyl cellulose in black shades, com rising treating the acetyl cellulose with dip enyl black base in presence of acetic acid and protective colloid, iand developing the dye on the acetyl celluose. 1,;

8. Proces s fio'if dyeing acetyl cellulose in black shades, comprising treating the acetyl cellulose with di henyl black base in presence of acetic aci at least one soluble c oride salt, and oping the dye on the acetyl cellulose.

1n testimony whereof I have hereunto subscribed my name.

' DR. RENE. CLAVEL.

aliphatic carboxylic acid,

dyeing acetyl cellulose in diphenyl black base inpresand developing the protective colloid, and devel-' 

